1. Field
One embodiment of the invention relates to a noise reduction apparatus and a noise reduction method for reducing noise components of a video signal.
2. Description of the Related Art
Noise reduction apparatuses have been used to reduce noise in a signal. For example, Japanese Patent Application Publication (KOKAI) No. 2001-136416 discloses a noise reduction apparatus (a signal processing apparatus) that reduces noise. Specifically, the conventional noise reduction apparatus performs motion correction on an input video signal to obtain a motion-corrected video signal based on a motion vector detected from the input video signal. The noise reduction apparatus detects the noise level of the input video signal based on the detection result of the motion vector, and obtain a difference signal between the input video signal and the motion-corrected video signal. The noise reduction apparatus performs nonlinear processing on the difference signal with intensity corresponding to the noise level, and combines the input video signal with the difference signal subjected to the nonlinear processing. Thus, the noise reduction apparatus reduces the noise.
With the conventional noise reduction apparatus, to reduce impulse noise having a predetermined amplitude or more, the sensitivity of the motion detection is adjusted such that it becomes more likely that an image is determined to be static. This causes a ghost around a moving object, and thus, image quality degrades.